(S1) A normal blade has a curving edge, and straight back. A dull back lets the wielder use fingers to concentrate force; it also makes the knife heavy and strong for its size. The curve concentrates force on a smaller area, making cutting easier. This knife can chop as well as pick and slice. This is also the best single-edged blade shape for thrusting, as the edge cuts a swath that the entire width of the knife can pass through without the spine having to push aside any material on its path, as a sheepsfoot or drop-point knife would.
(S2) A trailing-point knife has a back edge that curves upward to end above the spine. This lets a lightweight knife have a larger curve on its edge and indeed the whole of the knife may be curved. Such a knife is optimized for slicing or slashing. Trailing point blades provide a larger cutting area, or belly, and are common on skinning knives.
(S3) A drop point blade has a convex curve of the back towards the point. It handles much like the clip-point, though with a stronger point typically less suitable for piercing. Swiss army pocket knives often have drop-points on their larger blades.
(S4) A clip-point blade is like a normal blade with the back “clipped”. This clip can be either straight or concave. The back edge of the clip may have a false edge that could be sharpened to make a second edge. The sharp tip is useful as a pick, or for cutting in tight places. If the false edge is sharpened it increases the knife’s effectiveness in piercing. As well, having the tip closer to the centre of the blade allows greater control in piercing. The Bowie knife has a clip point blade and clip-points are common on pocket knives and other folding knives.
(S5) A sheepsfoot blade has a straight edge and a straight dull back that curves towards the edge at the end. It gives the most control, because the dull back edge is made to be held by fingers. Sheepsfoot blades were originally made to trim the hooves of sheep. Their shape bears no similarity to the foot of a sheep.
(S6) A Wharncliffe blade is similar in profile to a sheep’s foot but the curve of the back edge starts closer to the handle and is more gradual. Its blade is much thicker than a knife of comparable size. Wharncliffes were used by sailors, as the shape of the tip prevented accidental penetration of the work or the user’s hand with the sudden motion of a ship.
(S7) A spey point blade (once used for neutering livestock) has a single, sharp, straight edge that curves strongly upwards at the end to meet a short, dull, straight point from the dull back. With the curved end of the blade being closer to perpendicular to the blade’s axis than other knives and lacking a point, making penetration unlikely, spey blades are common on Trapper style pocketknives for skinning fur-bearing animals.
(C1) Leaf blade with a distinctive recurved “waist” adding some curved “belly” to the knife facilitating slicing as well as shifting weight towards the tip meaning that it is commonly used for throwing knives as well as improving chopping ability.
(C2) A spear point blade is a symmetrically-shaped blade with a point aligned with the centerline of the blade’s long axis. True spear-point blades are double-edged with a central spine, like a dagger or spear head. The spear point is one of the stronger blade point designs in terms of penetration stress, and is found on many thrusting knives such as the dagger. The term spear point is occasionally and confusingly used to describe small single-edged blades without a central spine, such as that of the pen knife, a small folding-blade pocket knife formerly used in sharpening quills for writing. Pen-knife may also nowadays refer to the blade pattern of some of larger pocket knife blades that would otherwise be termed drop-point designs.
(C3) A needle point blade has a sharply-tapered acuminated point. It is frequently found on daggers such as the stiletto (which had no sharpened edges) and the Fairbairn-Sykes fighting knife. Its long, narrow point reduces friction and increases the blade’s penetrative capabilities, but is liable to stick in bone and can break if abused. When the needle point is combined with a reinforced ‘T’ section running the length of the blade’s spine, it is called a reinforced tip. One example of a knife with a reinforced tip is the pesh-kabz.
(C5) Referred to in English speaking countries as a “tanto” or “tanto point” (a corruption of the Japanese word tantō though the tip bears no resemblance to a tantō) or a chisel point. (Chisel point only refers to the straightness of the edge that comprises the end of the blade and not to the knife edge being ground on just one side.) It is similar to, but not the same as, some early Japanese swords that had kamasu kissaki (“barracuda tip”), a nearly straight edge at the tip whereas the typical “tanto point” as found in the west has a straight edge. The barracuda tip sword was sharp but also fragile whereas modern tanto point are often advertised as being stronger at the tip for having nearly the whole thickness of the blade present until quite close to the end of the knife. Knife tests have shown that penetration ability of this style of blade is comparatively poor but it is possible, if the tip is strong, that more force can be applied allowing greater penetration without damaging the tip.
The lower illustration is a modified tanto where the end is clipped and often sharpened. This brings the tip closer to the centre of the blade increasing control of the blade and improves penetration potential by having a finer point and a sharpened back edge.
(C6) A hawkbill blade is sharpened on the inside edge and is similar to carpet and linoleum knives. The point will tear even if the rest of the knife is comparatively dull. The karambit from Far South-East Asia is a hawkbill knife which is held with the blade extending from the bottom of the fist and the tip facing forward. The outside edge of a karambit may be sharp and if so may also feature a backwards facing point.
(C7) An ulu (Inuit woman’s knife) knife is a sharpened segment of a circle. This blade type has no point, and has a handle in the middle. It is good for scraping, and sometimes chopping. The semi-circular version appears elsewhere in the world and is called a head knife. It is used in leatherworking both to scrape down leather (reducing thickness), and to make precise, rolling cuts for shapes other than straight lines. The circular version is a popular tool for slicing pizzas. One corner is placed at the edge of the pizza and the blade is rolled across in a diameter cut.